<?php

if (! defined('BASEPATH'))
    exit('No direct script access allowed');

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package CodeIgniter
 * @author ExpressionEngine Dev Team
 * @copyright Copyright (c) 2006 - 2012 EllisLab, Inc.
 * @license http://codeigniter.com/user_guide/license.html
 * @link http://codeigniter.com
 * @since Version 2.0
 * @filesource
 *
 */
    
// ------------------------------------------------------------------------

/**
 * CodeIgniter APC Caching Class
 *
 * @package CodeIgniter
 * @subpackage Libraries
 * @category Core
 * @author ExpressionEngine Dev Team
 * @link
 *
 */
class CI_Cache_apc extends CI_Driver
{

    /**
     * Get
     *
     * Look for a value in the cache. If it exists, return the data
     * if not, return FALSE
     *
     * @param
     *            string
     * @return mixed that is stored/FALSE on failure
     */
    public function get ($id)
    {
        $data = apc_fetch($id);
        
        return (is_array($data)) ? $data[0] : FALSE;
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * Cache Save
     *
     * @param
     *            string Unique Key
     * @param
     *            mixed Data to store
     * @param
     *            int Length of time (in seconds) to cache the data
     *            
     * @return boolean on success/false on failure
     */
    public function save ($id, $data, $ttl = 60)
    {
        return apc_store($id, array(
                $data,
                time(),
                $ttl
        ), $ttl);
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * Delete from Cache
     *
     * @param
     *            mixed unique identifier of the item in the cache
     * @param
     *            boolean true on success/false on failure
     */
    public function delete ($id)
    {
        return apc_delete($id);
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * Clean the cache
     *
     * @return boolean on failure/true on success
     */
    public function clean ()
    {
        return apc_clear_cache('user');
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * Cache Info
     *
     * @param
     *            string user/filehits
     * @return mixed on success, false on failure
     */
    public function cache_info ($type = NULL)
    {
        return apc_cache_info($type);
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * Get Cache Metadata
     *
     * @param
     *            mixed key to get cache metadata on
     * @return mixed on success/false on failure
     */
    public function get_metadata ($id)
    {
        $stored = apc_fetch($id);
        
        if (count($stored) !== 3) {
            return FALSE;
        }
        
        list ($data, $time, $ttl) = $stored;
        
        return array(
                'expire' => $time + $ttl,
                'mtime' => $time,
                'data' => $data
        );
    }
    
    // ------------------------------------------------------------------------
    
    /**
     * is_supported()
     *
     * Check to see if APC is available on this system, bail if it isn't.
     */
    public function is_supported ()
    {
        if (! extension_loaded('apc') or ini_get('apc.enabled') != "1") {
            log_message('error', 
                    'The APC PHP extension must be loaded to use APC Cache.');
            return FALSE;
        }
        
        return TRUE;
    }
    
    // ------------------------------------------------------------------------
}
// End Class

/* End of file Cache_apc.php */
/* Location: ./system/libraries/Cache/drivers/Cache_apc.php */
